This invention relates to flexible shelter structure such as tents and the like.
It is desirable in many flexible shelter structures to maximize the volume of the sheltered space defined by the structure, while at the same time maximizing the strength of the structure and minimizing its weight. These are particularly desirable characteristics in tents designed for mobile applications, such as backpacking.
Numerous flexible shelter and tent designs are described in the prior art. For example, various convex multi-poled tent structures are described in U.S. Pat. Nos. 3,986,519, 4,099,533, 4,265,260, and 4,414,993, all of which are owned by the inventor of the present invention. U.S. Pat. Nos. 3,986,519 and 4,099,533 both disclose dome-like structures composed of a plurality of flexible pole or rod elements maintained under tension in a generally arcuate shape, and an underlying membrane. Each structure includes at least two intersecting sets of such pole or rod elements. The rod or pole elements are held in fixed relationship at intersections by fittings secured to the underlying flexible membrane or sheath. The underlying membrane or sheath acts as a tension member to maintain the poles under tension.
U.S. Pat. Nos. 4,265,260 and 4,414,993 disclose a flexible vault structure which similarly includes a plurality of deformable resilient poles that are held under tension in generally arcuate shape by an underlying fabric member. U.S. Pat. No. 4,265,260 discloses the use of fabric sleeves in addition to fittings for coupling the poles to the underlying fabric member. This structure similarly lacks the added rigidity and strength of the structure of the present invention, which includes additional tension elements.
Each of the foregoing structures employ a plurality of flexible, resilient poles, the opposite ends of which terminate in a common plane or base, e.g., the ground. The poles add weight to the overall structure. Additionally, since the poles are typically maintained in a generally arcuate shape under tension, the arch of the poles essentially determines and limits the volume of the internal sheltered space of the structure. The materials used to manufacture the poles can also be quite expensive.
What is needed and what has been devised is a flexible shelter structure employing one or more flexible main poles, in which the sheltered space defined by the structure is not limited by the arcuate shapes of the main poles and may in fact be significantly increased, and in which the amount of pole material is reduced, thereby significantly reducing the weight and cost of the structure.